| Hypopygus | |
|---|---|
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Order: | Gymnotiformes |
| Family: | Rhamphichthyidae |
| Genus: | Hypopygus Hoedeman, 1962 [1] |
| Type species | |
| Hypopygus lepturus Hoedeman, 1962 [1] | |
| Synonyms [1] | |
Stegostenopos Triques, 1997 | |
Hypopygus is a genus of South American gymnotiform knifefishes native to the Amazon, Orinoco and upper Paraguay basins, as well as rivers in the Guianas. [2] [3] They are often common, and found near submerged roots, aquatic vegetation and leaf-litter in streams, edges of rivers and floodplains. [2] They are regularly found among vegetation in floating meadows, a habitat that often contains little oxygen, but they are well-adapted to this. [4]
They are well-camouflaged and brown in color with a banded/mottled pattern. [2] [3] [5] They generally resemble the related Steatogenys , but are smaller, [6] reaching up to 5.9–12.2 cm (2.3–4.8 in) in total length depending on the exact species of Hypopygus. [7] The smallest is H. hoedemani, which is the second-smallest knifefish, [2] after Microsternarchus brevis. [8] They are nocturnal and feed on small invertebrates. During the day they remain hidden, often in groups that may number several dozen individuals. [2]
